Regression models to relate excavated root counts of trees in two pavement treatments as compared to ground penetrating radar counts of root signals. As a ground-truth verification study, the expected slope would be equal to 1 (one root for each signal) with an intercept of zero. In the regression models presented, y = excavated root count, and x = GPR count.
Model | Equation | n | S.E. slope | p-value Ho slope = 1.0 | S. E. constant | p-value Ho constant = 0 | r2 |
---|---|---|---|---|---|---|---|
Experiment-wide (mixed effect model) | y = 0.84x + 0.26 | 80 | 0.05 | 0.004 | 0.36 | 0.4765 | 0.88 |
CU-Soil | |||||||
scan section | y = 0.83x + 0.97 | 40 | 0.07 | 0.022 | 0.46 | 0.435 | 0.81 |
tree | y = 0.96x + 3.8 | 5 | 0.23 | 0.87 | 10.21 | 0.735 | 0.86 |
Silt loam | |||||||
scan section | y = 0.77x − 0.12 | 40 | 0.09 | 0.017 | 0.43 | 0.7846 | 0.76 |
tree | y = 2.13x − 40.6 | 5 | 0.95 | 0.30 | 26.1 | 0.217 | 0.63 |